Finger plate locking means



May 2, 1933. A. w. HULSON FINGER PLATE LOCKING MEANS Filed NOV. 2, 1931 aummtoz AHu Z8072 un/ 344000 :v w ml? Patented May 2, 1933 UNITED STATES ARTHUR w. EULSON, or KEOKUK, IOWA FIlINGER PLATE LOCKING MEANS Application filed November 2, 1931. Serial No. 572,652.

The invention relates to grates of types provided with finger plates removably carried by finger bars or other supports. It is quite common-in the art to provide the finger bar or other support and the finger plates with means which interlock when the plates are slid longitudinally of the support from a predetermined point at which all of said plates are initially engaged with the support. At the finger-plate-receiving point, the support is necessarily free of the means which interlocks with the finger plates, for other wise said plates could not be placed on said support. This lock-free condition of the plate-receiving portion of the support, necessitates some additional provision for locking the last applied finger plate to the support, usual \requiring a specially constructed finger plate for plates to be applied last, and

then looked. My invention however, aims to provide a new and improved and generally simplified structure whereby all of the finger plates may be of identical form if desired, and whereby it is only. necessary to force or drive the last plate into, position to efi'ect locking thereof on the support.

With the foregoing in view, the invention resides in the novel subject matter hereinafter described and claimed, description being accomplished by reference to the accompanying drawing.

, Fig. 1 is a side elevation of a finger plate constructed in accordance with the present invention.

Fig. 2 is a vertical sectional view substantially on line 22 of Fig. 1, showing a plurality of the finger plates in position'upon the support andillustrating the last finger plate in readiness to be finally forced into the position which it is to occupy.

Fig. 3 is a view similar to Fig. 2 but showing the relation which the various finger plates assume when they have all been applied.

Fig. 4 is a detail sectional view similar to a ortion of Fig. 3 but showing a slightly di erent construction.

In the drawing above briefly described, the numerals 5 denote a plurality of finger plates whose upper portions are provided with intermeshing lateral lugs 6 and 7 in the present disclosure. The relation and action of these lugs however, form no parts of the present invention, and are disclosed and claimed in my U. S. application Serial No. 572,650, filed November 2, 1931. The lower edge of each finger plate 5 is provided with a notch 8 to receive a finger bar or other support 9. The finger plates are applied to the support 9 at the point 10, preferably between the ends of said support, and said finger plates and support are provided with coacting means ada ted to interlock when any plate is slid longitudinally of the bar from said point 10. For illustrative purposes, the interlocking means is herein shown as consisting of longitudinal ribs 11 on the support 9 and grooves 12 in opposed sides of the notches 8. At the point 10, the support 9 is of course free of ribs such as 11, allowing any finger plate to be placed downwardly upon the support and then slid longitudinally o the latter, into the position which it is to occupy.

In the present showing, one flat side of each finger plate 5 is provided with a socket 13 (or 13 in Fig. 4), each socket 13 being provided with a horizontal downwardly facing side wall 14, while the socket 13 is provided with an upwardly facing horizontal wall 14. Each socket 13 preferably opens into the upper end of the notch 8, but the socket 13 may be free of communication with said notch.

The other vertical side of each finger plate 5 is provided with an integral projecting lug 15 (or with a lug such as 15 of Fig. 4). Each lug 15 is provided with a horizontal upper surface 16 and with an inclined lower side or cam surface 17 whereas the lug 15 is provided with a horizontal lower surface 16 and with an inclined upper side or cam surface 17. The various lugs and sockets are adapted to interlock with each other as shown in Figs. 3 and 4, when all of the fingers are prop erly applied to the support 9.

After all of the fingers have been posi tioned except the last one, this last finger must be forced or driven into place, during which operation, the beveled surface or cam 17 or 17 engages the next adjacent finger plate in a manner which will be clear from Fig. 2, so that when the last finger plate is finally forced home, it will laterally force the previously applied finger plates into such close relation as to admit said last plate. As soon as this plate is positioned so that the lug and socket thereof can interlock with the adjacent socket and lug respectively, the tight abutting contact of the various plates is relieved and they will more or less spring into slightly spaced relation, as seen in Fig. 3, the various lugs and sockets being then interlocked with each other. It is thus insured that the last plate cannot become upwardly shifted from the support 9, even though its grooves 12 engage no ribs such as 11. Whenever one or more of the finger plates must be removed on account of damage, and replaced with others, it is an easy matter to break the damaged plate or plates from the support 0, giving ample room for removing any other plates and applying the new plates.

lVhile it is preferable that all of the finger plates 5 he provided with the lugs and sockets, it is of course possible to construct most of them with plain abutting faces and to so construct the last applied plate and an adj acent plate as to cause a lug and socket thereof to interlock when said last plate is driven into position.

lVhen the specific plate construction herein disclosed, is employed, the lateral lugs 6 and 7 at the upper portion of the last applied plate, must of course force the adjacent plates apart at their upper portions before the lugs 7 of the last applied plate can clear the lugs 6 of the adjacent plates, but such shifting of the upper portions of the finger plates is permitted, due to the fact that they are all more or less rough castings and do not accurately fit upon the support 9.

\Vhile the details herein disclosed may be considered as preferred, it is to be understood that within the scope of the invention as claimed, variations may be made. Furthermore, it may be explained that the improved finger plates may be used either upon a grate embodying finger bars, or may constitute portions of a chain link grate.

I claim 1. A finger plate for a grate having a downwardly opening notch to receive a finger plate support, one side of said finger plate being provided with a lateral lug adapted to interlock with a socket in an adjacent finger plate, said lug having a horizontal surface to abut a wall of the socket and a cam surface to laterally force the adjacent plate.

2. A finger plate for a grate having a downwardly opening notch to receive a finger plate support, one side of said finger plate being provided with a socket adapted to interlock with a lug on an adjacent finger plate, said socket having a horizontal wall to-abut the lug, the other side of said finger plate having a lateral lug opposite said socket for reception in a socket of another adjacent finger plate, said lug having a horizontal surface in substantially the same plane as said horizontal wall of said socket, said lug being provided also with a cam surface to laterally force the finger plate in whose socket said lug is receivable.

3. An improvement in a grate of the type embodying a finger-plate support and abutting finger-plates having downwardly opening notches receiving said support, said support and all of said plates except one having interlocked portions preventing upward movement of all except said one of said plates, said one plate and said support being free of interlocking engagement with each other said improvement comprising an interfitting lug and socket on said one plate and an adjacent plate respectively, for holding said one plate against upward movement.

4. An improvement in a grate of the type embodying a finger-plate support and abutting finger-plates having downwardly opening notches receiving said support, said support and all of said plates except one having interlocked portions preventing upward movement of all except said one of said plates. said one plate and said support being free of interlocking engagement with each other: said improvement comprising an interfitting lug and socket on said one plate and an adjacent plate respectively, for holding said one plate against upward movement, said lug and socket having abutting horizontal surfaces preventing said upward movement of said one plate, said lug having a cam surface for the purpose set forth.

ARTHUR W. HULSON. 

